Journal article
Dietary nitrate does not acutely enhance skeletal muscle blood flow and vasodilation in the lower limbs of older adults during single-limb exercise
European journal of applied physiology, Vol.120(6), pp.1357-1369
06/2020
DOI: 10.1007/s00421-020-04368-8
PMID: 32303829
Abstract
Blood flow (BF) and vasodilator responses to knee-extension exercise are attenuated in older adults across an exercise transient (onset, kinetics, and steady-state), and reduced nitric oxide bioavailability (NO) has been hypothesized to be a primary mechanism contributing to this attenuation. We tested the hypothesis acute dietary nitrate (NO
) supplementation (~ 4.03 mmol NO
and 0.29 mmol NO
) would improve leg vasodilator responses across an exercise transient during lower limb exercise in older adults.
Older (n = 10) untrained adults performed single and rhythmic knee-extension contractions at 20% and 40% work-rate maximum (WR
) prior to and 2-h after consuming a NO
or placebo beverage in a double-blind, randomized fashion. Femoral artery BF was measured by Doppler ultrasound. Vascular conductance was calculated using BF and mean arterial pressure.
Acute ingestion of dietary NO
enhanced plasma [NO
] and [NO
] (P < 0.05). Neither dietary NO
or placebo enhanced vasodilator responses at the onset of exercise or during steady state at 20% and 40% WR
(P > 0.05). Leg vasodilator kinetics during rhythmic exercise remained unchanged following NO
and placebo ingestion (P > 0.05).
The key findings of this study are that despite increasing plasma [NO
] and [NO
]
acute dietary NO
intake had no effect on (1) rapid hyperaemic or vasodilator responses at the onset of exercise; (2) hyperaemic and vasodilator responses during steady-state submaximal exercise; or (3) kinetics of vasodilation preceding steady-state responses. Collectively, these findings suggest that low dose dietary NO
supplementation does not improve hyperaemic and vasodilator responses across an exercise transient in older adults.
Details
- Title: Subtitle
- Dietary nitrate does not acutely enhance skeletal muscle blood flow and vasodilation in the lower limbs of older adults during single-limb exercise
- Creators
- William E Hughes - University of IowaNicholas T Kruse - University of IowaKenichi Ueda - University of IowaAndrew J Feider - University of IowaSatoshi Hanada - University of IowaJoshua M Bock - University of IowaDarren P Casey - University of Iowa
- Resource Type
- Journal article
- Publication Details
- European journal of applied physiology, Vol.120(6), pp.1357-1369
- DOI
- 10.1007/s00421-020-04368-8
- PMID
- 32303829
- ISSN
- 1439-6319
- eISSN
- 1439-6327
- Grant note
- 1-16-1CTA-015 / American Diabetes Association
- Language
- English
- Date published
- 06/2020
- Academic Unit
- Anesthesia; Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984294952302771
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